The invention pertains to the field of jet technology, primarily to installations for producing a vacuum in rectification columns destined for the distillation of various separable liquid products.
A method of operation of a pumping-ejector vacuum system for crude oil rectification is known, which consists of feeding of a separable liquid product into a vacuum rectification column, separation of the liquid product into a vapor fraction and at least one liquid fraction, delivery of the liquid fraction into the nozzle of a liquid-gas jet apparatus by a pump, evacuation of the vapor fraction by the liquid-gas jet apparatus, mixing of the vapors with a motive liquid in the jet apparatus and condensation of easy-condensable components of the vapors in the motive liquid, and separation of the motive liquid from vapors in a separator (see U.S. Pat. No. 1,567,429, M cl. C 10 C7100, 1925).
However, this method of operation of a pumping-ejector installation is characterised by high power inputs and high consumption of the motive liquid, which must be purified before discharge to drainage.
There is also another known method of operation of a pumping-ejector installation for the distillation of a liquid product. This method includes delivery of a separable liquid product into a vacuum rectification column, separation of the liquid product into a vapor phase and at least one liquid fraction, delivery of the liquid fraction into the nozzle of a liquid-gas jet apparatus by a pump, evacuation of the vapor phase by the liquid-gas jet apparatus, mixing of the vapour phase with a motive liquid in the jet apparatus with simultaneous compression of the vapor phase and forming of a liquid-vapor mixture, and separation of the mediums' mixture into a liquid medium and a compressed gaseous component in a separator (see RU patent, 2048156, cl. B01 D3/10, 1995).
According to this method, evacuation of the vapor phase from the rectification column is effected by the liquid-gas jet apparatus. However, evacuation of the vapor phase by the liquid-gas jet apparatus is not accompanied by complete condensation of easy-condensable components of the vapor phase, which reduces output of a light fraction as the base product of the vacuum rectification column. Such is conditioned by the fact that correlation between pressure in the vacuum rectification column, pressure in the separator and saturated vapour pressure of the motive liquid, which is delivered into the nozzle of the liquid-gas jet apparatus, is not optimal.